mod: simplify Container and Element creation with updated zterm behavior

src/root.zig

@@ -6,15 +6,24 @@
 
 pub const Event = union(enum) {};
 
-pub fn Container(App: type, gpa: Allocator) !App.Container {
-    // TODO create container structure
-    // -> might require some additional arguments
-    return try .init(gpa, .{}, .{});
+pub fn Container(App: type, gpa: Allocator, element: *elements.Root(App), tree: *elements.Tree(App), diffs: *App.Scrollable) !App.Container {
+    var root: App.Container = try .init(gpa, .{
+        .layout = .{
+            .direction = .horizontal,
+            .separator = .{
+                .enabled = true,
+            },
+        },
+    }, element.element());
+    try root.append(try .init(gpa, .{}, tree.element()));
+    try root.append(try .init(gpa, .{}, diffs.element()));
+    return root;
 }
 
 const std = @import("std");
 const Allocator = std.mem.Allocator;
 
+pub const elements = @import("elements.zig");
 pub const Model = @import("model.zig");
 
 test {